package com.x.calendar.common.excel.reader;

import java.io.InputStream;
import java.math.BigDecimal;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.Iterator;
import java.util.List;

import org.apache.poi.hssf.usermodel.HSSFDateUtil;
import org.apache.poi.openxml4j.opc.OPCPackage;
import org.apache.poi.xssf.eventusermodel.XSSFReader;
import org.apache.poi.xssf.model.SharedStringsTable;
import org.apache.poi.xssf.usermodel.XSSFRichTextString;
import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;
import org.xml.sax.helpers.XMLReaderFactory;

/**
 * 抽象Excel2007读取器，excel2007的底层数据结构是xml文件，采用SAX的事件驱动的方法解析
 * xml，需要继承DefaultHandler，在遇到文件内容时，事件会触发，这种做法可以大大降低
 * 内存的耗费，特别使用于大数据量的文件。
 *
 */
public class Excel2007Reader extends DefaultHandler {
	//共享字符串表
	private SharedStringsTable sst;
	//上一次的内容
	private String lastContents;
	
	private boolean nextIsString;

	private int sheetIndex = -1;
	
	private List<String> rowlist = new ArrayList<String>();
	//当前行
	private int curRow = 0;
	//当前列
	private int curCol = 0;
	//日期标志
	private boolean dateFlag;
	//数字标志
	private boolean numberFlag;
	
	private boolean isTElement;
	
	private String fileKey;
	private int startRow;
	private IRowReader rowReader;
	
	public void setRowReader(IRowReader rowReader, String fileKey, int startRow){
		this.rowReader = rowReader;
		this.fileKey = fileKey;
		this.startRow = startRow;
	}
	
	/**只遍历一个电子表格，其中sheetId为要遍历的sheet索引，从1开始，1-3
	 * @param filename
	 * @param sheetId
	 * @throws Exception
	 */
	public void processOneSheet(String filename,int sheetId) throws Exception {
		OPCPackage pkg = OPCPackage.open(filename);
		XSSFReader r = new XSSFReader(pkg);
		SharedStringsTable sst = r.getSharedStringsTable();
		XMLReader parser = fetchSheetParser(sst);
		
		// 根据 rId# 或 rSheet# 查找sheet
		InputStream sheet2 = r.getSheet( "rId"+sheetId);
		sheetIndex++;
		InputSource sheetSource = new InputSource(sheet2);
		parser.parse(sheetSource);
		sheet2.close();
	}

	/**
	 * 遍历工作簿中所有的电子表格
	 * @param filename
	 * @param fileKey 
	 * @throws Exception
	 */
	public void process( String filename ) throws Exception {
		OPCPackage pkg = OPCPackage.open( filename );
		XSSFReader r = new XSSFReader(pkg);
		SharedStringsTable sst = r.getSharedStringsTable();
		XMLReader parser = fetchSheetParser(sst);
		Iterator<InputStream> sheets = r.getSheetsData();
		while (sheets.hasNext()) {
			curRow = 0;
			sheetIndex++;
			InputStream sheet = sheets.next();
			InputSource sheetSource = new InputSource(sheet);
			parser.parse( sheetSource );
			sheet.close();
		}
		//数据读取完成
	}
	/**
	 * 遍历工作簿中所有的电子表格
	 * @param is
	 * @param fileKey 
	 * @throws Exception
	 */
	public void process( InputStream is ) throws Exception {
		OPCPackage pkg = OPCPackage.open( is );
		XSSFReader r = new XSSFReader(pkg);
		SharedStringsTable sst = r.getSharedStringsTable();
		XMLReader parser = fetchSheetParser(sst);
		Iterator<InputStream> sheets = r.getSheetsData();
		while (sheets.hasNext()) {
			curRow = 0;
			sheetIndex++;
			InputStream sheet = sheets.next();
			InputSource sheetSource = new InputSource(sheet);
			parser.parse( sheetSource );
			sheet.close();
		}
		//数据读取完成
	}
	public XMLReader fetchSheetParser(SharedStringsTable sst) throws SAXException {
		XMLReader parser = XMLReaderFactory.createXMLReader( "org.apache.xerces.parsers.SAXParser" );
		this.sst = sst;
		parser.setContentHandler(this);
		return parser;
	}

	public void startElement(String uri, String localName, String name, Attributes attributes) throws SAXException {
		
		// c => 单元格
		if ( "c".equals(name)) {
			// 如果下一个元素是 SST 的索引，则将nextIsString标记为true
			String cellType = attributes.getValue( "t" );
			if ( "s".equals(cellType)) {
				nextIsString = true;
			} else {
				nextIsString = false;
			}
			//日期格式
			String cellDateType = attributes.getValue( "s" );
			if ( "1".equals(cellDateType)){
				dateFlag = true;
			} else {
				dateFlag = false;
			}
			String cellNumberType = attributes.getValue( "s" );
			if( "2".equals(cellNumberType)){
				numberFlag = true;
			} else {
				numberFlag = false;
			}
			
		}
		//当元素为t时
		if( "t".equals(name)){
			isTElement = true;
		} else {
			isTElement = false;
		}
		
		// 置空
		lastContents = "";
	}

	public void endElement(String uri, String localName, String name)
			throws SAXException {
		
		// 根据SST的索引值的到单元格的真正要存储的字符串
		// 这时characters()方法可能会被调用多次
		if (nextIsString) {
			try {
				int idx = Integer.parseInt(lastContents);
				lastContents = new XSSFRichTextString(sst.getEntryAt(idx))
						.toString();
			} catch (Exception e) {

			}
		} 
		//t元素也包含字符串
		if(isTElement){
			String value = lastContents.trim();
			rowlist.add(curCol, value);
			curCol++;
			isTElement = false;
			// v => 单元格的值，如果单元格是字符串则v标签的值为该字符串在SST中的索引
			// 将单元格内容加入rowlist中，在这之前先去掉字符串前后的空白符
		} else if ( "v".equals(name)) {
			String value = lastContents.trim();
			value = value.equals( "" )?" ":value;
			//日期格式处理
			if(dateFlag){
				try{
					Date date = HSSFDateUtil.getJavaDate(Double.valueOf(value));
					SimpleDateFormat dateFormat = new SimpleDateFormat( "dd/MM/yyyy" );
					value = dateFormat.format(date);
				}catch(Exception e){
					
				}
			} 
			//数字类型处理
			if(numberFlag){
				try{
					BigDecimal bd = new BigDecimal(value);
					value = bd.setScale(3,BigDecimal.ROUND_UP).toString();
				}catch(Exception e){
					
				}
			}
			rowlist.add(curCol, value);
			curCol++;
		}else {
			//如果标签名称为 row ，这说明已到行尾，调用 optRows() 方法
			if (name.equals( "row" )) {
				
				rowReader.getRows(sheetIndex,curRow,rowlist, this.fileKey, this.startRow );
				rowlist.clear();
				curRow++;
				curCol = 0;
			}
		}
		
	}

	public void characters(char[] ch, int start, int length)
			throws SAXException {
		//得到单元格内容的值
		lastContents += new String(ch, start, length);
	}
}
